The patented annual calendar was launched in 1996 and has been a success story for the past 20 years. Indicating the day of the week, the date and the month, and requiring correction only once a year, this ingenious mechanism has emerged as one of Patek Philippe’s flagship models. It offers a choice of different displays and nuances of style, always combining elegant lines, noble materials and lavish attention to finish. Self-winding mechanical movement. Caliber 324 S IRM QA LU. Day and month by hands. Date in an aperture. Sweep seconds hand. Cream lacquered dial, gold applied hour markers and numerals. 18k yellow gold case. Sapphire-crystal case back. Water resistant to 30 m. Case diameter: 39 mm. Height: 11.23 mm. Matte gabardine brown alligator strap. Fold-over clasp.